The method of growing a ceramic product by an oxidation reaction is disclosed generally in copending Commonly Owned U.S. patent application Ser. No. 818,943, filed Jan. 15, 1986, and its ancestor applications (now abandoned), all in the names of Marc S. Newkirk et al. and entitled "Novel Ceramic Materials and Methods of Making the Same." U.S. patent application No. 818,943, issued to U.S. Pat. No. 4,713,360, on Dec. 15, 1978. These applications and patent disclose the method of producing self-supporting ceramic bodies grown as the oxidation reaction product of a parent metal precursor which may be enhanced by the use of an alloyed dopant. Molten parent metal is reacted with a vapor-phase oxidant to form the oxidation reaction product. In the appropriate temperature range, molten metal is progressively drawn through the oxidation reaction product and into contact with the oxidant thereby continuing to form additional oxidation reaction product and developing the ceramic body. The method was improved upon by the use of external dopants applied to the surface of the precursor parent metal as disclosed in Commonly Owned U.S. application Ser. No. 822,999, filed Jan. 27, 1986, and its ancestor applications (now abandoned), all in the names of Marc S. Newkirk et al. and entitled "Methods of Making Self-Supporting Ceramic Materials." U.S. Pat. No. 4,853,352, issued on Aug. 1, 1989, from U.S. patent application Ser. No. 220,935, which was filed on Jun. 23, 1988, as a continuation of U.S. patent application Ser. No. 822,999.
The method of fabricating a ceramic composite product by infiltrating an inert filler material with an oxidation reaction product produced in accordance with the procedures disclosed in the above applications is disclosed generally in U.S. Pat. No. 4,851,375 which issued on Jul. 25, 1989, from Commonly Owned U.S. patent application Ser. No. 819,397, filed Jan. 17, 1986, as a continuation-in-part application of Ser. No. 697,876, filed Feb. 4, 1985 (now abandoned), both in the names of Marc S. Newkirk et al. and entitled "Composite Ceramic Articles and Methods of Making Same". These applications and patent disclose a method for fabricating a ceramic composite by growing an oxidation reaction product into an inert filler by placing a mass of said filler adjacent to a parent metal and reacting the parent metal in accordance with the oxidation reaction disclosed above.
Barrier materials may be employed to substantially inhibit or prevent the growth of the oxidation reaction product in order to facilitate obtaining a net shape ceramic product. This concept was disclosed in copending Commonly owned U.S. Pat. No. 4,923,832, which issued on May 8, 1990, from U.S. patent application Ser. No. 861,024, filed May 8, 1986, in the names of Marc S. Newkirk et al. and entitled "Method of Making Shaped Ceramic Composites with the Use of a Barrier".
The entire disclosures of each of the foregoing Commonly Owned Patent Applications and patents, which are assigned to the same owner, are expressly incorporated herein by reference.
There is an increased interest in substituting ceramics for metals because, with respect to certain properties, ceramics are superior to metals. There are, however, several known limitations or difficulties in making this substitution such as scaling versatility, capability to produce complex shapes, satisfying the properties required for the end use application, and costs. The above-described Commonly Owned Patent Applications and patents overcome many of these difficulties or limitations and provide novel methods for reliably producing ceramic materials, including composites.
However, the ability to grow an oxidation reaction product having a defined shape or geometry in the absence of a preform still presents certain difficulties. In many cases, post-process shaping of the oxidation reaction product is necessary to attain a shape. The present invention provides a reliable method for growing the oxidation reaction product to a predetermined shape or geometry.